Compare Bytes Left-Adjusted (CMPBLA)

Op Code (Hex)	Extender	Operand 1	Operand 2	Operand 3 [4, 5]
CMPBLAB 1CC2	Branch options	Compare operand 1	Compare operand 2	Branch targets

CMPBLAI 18C2	Indicator options	Compare operand 1	Compare operand 2	Indicator targets

Operand 1: Numeric scalar or character scalar.

Operand 2: Numeric scalar or character scalar.

Operand 3 [4, 5]:

Branch Form-Instruction number, relative instruction number, branch point, or instruction pointer.
Indicator Form-Numeric variable scalar or character variable scalar.

Description: This instruction compares the logical string values of two left-adjusted compare operands. The logical string value of the first compare operand is compared with the logical string value of the second compare operand (no padding done). Based on the comparison, the resulting condition is used with the extender field to:

Transfer control conditionally to the instruction indicated in one of the branch target operands (branch form).
Assign a value to each of the indicator operands (indicator form).

The compare operands can be either character or numeric. Any numeric operands are interpreted as logical character strings.

The compare operands are compared byte by byte, from left to right with no numeric conversions performed. The length of the operation is equal to the length of the shorter of the two compare operands. The comparison begins with the leftmost byte of each of the compare operands and proceeds until all bytes of the shorter compare operand have been compared or until the first unequal pair of bytes is encountered.

Substring operand references that allow for a null substring reference (a length value of zero) may be specified for operands 1 and 2. The effect of specifying a null substring reference for either or both compare operands is that the instruction's resultant condition is equal.

Resultant Conditions: The scalar first compare operand's string value is one of the following as compared to the second compare operand.

Higher
Lower
Equal

Authorization Required

None

Lock Enforcement

None

Exceptions

06 Addressing

0601 Space Addressing Violation
0602 Boundary Alignment
0603 Range

08 Argument/Parameter

0801 Parameter Reference Violation

10 Damage Encountered

1004 System Object Damage State
1044 Partial System Object Damage

1C Machine-Dependent

1C03 Machine Storage Limit Exceeded

20 Machine Support

2002 Machine Check
2003 Function Check

22 Object Access

2201 Object Not Found
2202 Object Destroyed
2203 Object Suspended
2208 Object Compressed
220B Object Not Available

24 Pointer Specification

2401 Pointer Does Not Exist
2402 Pointer Type Invalid

2C Program Execution

2C04 Branch Target Invalid

2E Resource Control Limit

2E01 User Profile Storage Limit Exceeded

36 Space Management

3601 Space Extension/Truncation

44 Protection Violation

4401 Object Domain or Hardware Storage Protection Violation